Prior art workers have devised many types of hold down clamps. Examples of prior art hold down clamps are taught in U.S. Pat. Nos. 2,085,235; 2,759,503; 2,785,709 and 4,658,686. While the prior art hold down clamps serve their purpose well, they are generally directed to a single function, or a limited number of functions and therefore lack versatility.
The present invention is directed to a multi-purpose hold down clamp which is extremely simple in construction and easy to manufacture. At the same time, however, the hold down clamp is capable of a number of modes of use. For example, the hold down clamp may be removably screwed or bolted to a work surface, serving as a stationary clamp. The clamp is provided with a planar base and is capable of being manually shifted in any direction along a work surface or power tool table in a free floating manner.
Many of the prior art hold down clamps are provided with guide bars which are adapted to be received in the guide slot of the table of a power tool. Many of these prior art clamps will not function without a guide bar. The guide bar is adapted to be slidably received in the guide slot in the tool table and the guide bar and guide slot determine a single rectilinear path of travel for the hold down clamp. As a result of this, such hold down clamps are not suitable for sanding and drilling operations.
The hold down clamp of the present invention is provided with a removable T-guide comprising a pair of rectilinear bars joined together one above the other. For example, the bars of the T-guide may be permanently joined together at right angles with respect to each other. In this instance, the lower guide bar is adapted to be slidably received in guide slot of the tool table and the upper guide bar is adapted to be received in a central longitudinal slot formed in the base of the hold down clamp, itself. This arrangement permits the hold down clamp of the present invention to have two distinct guided rectilinear paths of travel. The first path of travel is determined by the sliding movement of the lower bar of the T-guide in the guide slot of the tool table. The second rectilinear guided path of travel is determined by the upper bar of the T-guide slidably mounted in the slot of the base of the hold down clamp. This enables the hold down clamp of the present invention to be used with the table of a band saw or a belt, disc or edge sander, having at least one guide slot formed in the table. This will be further and fully explained hereinafter.
The upper and lower bars of the T-guide may be joined together by a flathead machine screw in an adjustable fashion. For example, the upper bar of the T-guide may be oriented with respect to the lower bar from a position wherein the upper bar is perpendicular to the lower bar, through a range of oblique angles, to a position wherein the upper bar is parallel to and overlies the lower bar. When this is the case, the hold down clamp of the present invention is not only capable of two distinct rectilinear guided paths of travel, but the second rectilinear guided path of travel is adjustable with respect to the first. Again, this will be fully described hereinafter.
From the above, it will be apparent that the multi-purpose hold down clamp of the present invention is capable of a number of modes of use. Moreover, when the hold down clamp is used in conjunction with the T-guide and a tool table provided with at least one guide slot, the hold down clamp will be capable of two distinct rectilinear paths of travel. Furthermore, if desired, the second rectilinear guided path of travel may be adjustable with respect to the first. The hold down clamp may be used with a single workpiece, or multiple workpieces which are to be identically cut or sanded. The word, "workpiece," as used herein and in the claims, should be considered to refer to a single piece or multiple pieces.